JP2016073444A - mask - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mask that can improve safety and comfort/efficiency of work.SOLUTION: A mask according to one aspect of the invention includes a mask body having a nose covering part, and a face seal bonded to a face contact edge of the mask body. The nose covering part is provided between a first axis line passing through a nose bridge contact part that comes in contact with the nose bridge of a wearer and a jaw contact part that comes in contact with the jaw of the wearer, and a second axis line passing through the nose bridge contact part, whose angle with respect to the first axis line is 65 degrees or less. The surface area of the mask body is 1.5 or more times the area of an opening surrounded by the face contact edge, and the face seal includes a water absorption part.SELECTED DRAWING: Figure 1

Description

  One aspect of the present invention relates to a mask.

  Conventionally, techniques related to mask function improvement and additional functions are known. For example, Patent Documents 1 and 2 describe disposable masks that can be softly fitted to the wearer's face. These masks are provided with a face pad. Further, for example, Patent Document 3 describes a mask that can prevent dust and viruses from entering from a gap between a mask body and a wearer's face. This mask includes a breathable face that is bonded and integrated with the mask body. The breathable face is present in a manner that allows contact with the wearer's face on the inside air side of the mask body.

JP 2006-149739 A JP 2004-242905 A JP 2012-161524 A

  In field work in factories and the like, safety, work comfort and efficiency are improved every day. For example, a mask worn by an operator in a factory is required to have high collection efficiency as a basic performance. This collection efficiency is one of the factors related to the safety of workers in terms of preventing inhalation of dust and the like. The collection efficiency is set in the official standard, and a mask that satisfies the standard is accepted as a certified product. In addition, the visibility of workers during work is an important factor in work safety. Therefore, it is desirable that the mask worn on the operator's face does not hinder the operator's view. In addition, the operator is required to maintain high attention. Therefore, it is desired that the mask worn on the face of the operator is reduced in discomfort due to wearing the mask so as to increase comfort during work and maintain attention. Examples of the discomfort include a feeling that the face is pressed by the mask, wetness of the mask in contact with the face, obstruction of breathing by wearing the mask, and penetration of the mask into the operator's field of view. Furthermore, from the viewpoint of work efficiency, it is desirable to increase the proportion of time during which work is performed continuously and work that is originally required. The time spent for exchanging the mask is not the time for performing the work that is originally required. Therefore, the mask once worn tends to be worn continuously and for a long time. Accordingly, the mask is required to continue to exhibit the function of collecting dust even when worn for a long time and to continue to function effectively in other performances. Thus, in order to improve safety, work comfort and efficiency in field work, the mask requires various performances including collection efficiency.

  On the other hand, the performance required for the above-described mask is often in a mutually contradictory relationship. Therefore, conventionally, there has been a tendency to develop a mask for specific performance improvement in accordance with the application in which the mask is used. For example, the masks of Patent Documents 1 and 2 are intended to provide a good wearing feeling by providing a face-contact pad. However, a mask specialized for a specific function does not contribute to all the performance improvements required for the mask, so when performing actual work, multiple masks can be used depending on the work application and purpose. It may be necessary to prepare a mask or change the mask during work. Accordingly, there is a need for a mask that can realize all the functions required for the mask in a well-balanced manner.

  Therefore, an object of the present invention is to provide a mask capable of improving safety, work comfort and efficiency.

  A mask according to one aspect of the present invention includes a mask body having a nose cover portion and a face seal joined to a face contact edge of the mask body, and the nose cover portion contacts the nose bridge of the wearer. And a first axis passing through the chin contact portion that contacts the wearer's chin and a second axis passing through the nasal bridge contact portion and having an angle with respect to the first axis of 65 degrees or less, The surface area of the mask main body is 1.5 times or more the area of the opening surrounded by the face contact edge, and the face seal has a water absorbing part.

  In the mask according to one aspect of the present invention, since the face seal is joined to the mask body, the mask is in surface contact with the wearer's face (the face that the face seal forms is in contact with the face to be worn) ). Therefore, since the pressure load on the face generated during wearing is reduced, pain during long-time wearing can be reduced. On the other hand, when a face seal is provided, it is generally difficult for the wearer's face to enter the mask body when wearing the mask. In this case, if the surface area of the mask main body is to be maintained from the viewpoint of securing the collection efficiency, the outer shape (apparent) shape of the mask main body tends to increase. Also, from the viewpoint of ensuring ease of breathing, the outer shape of the mask body is similarly increased. However, when the outer shape of the mask main body becomes large, the mask main body enters the wearer's field of view, which may hinder the wearer's visual field during work. Therefore, in a mask provided with a face seal, there may be a conflicting problem between the point of collection efficiency and ease of breathing and the point of view visibility. Therefore, in the mask according to one aspect of the present invention, the nose cover portion is placed between the first axis and the second axis in order to satisfy both the characteristics of securing the field of view, collection efficiency, and ease of breathing. Furthermore, the surface area of the mask body is 1.5 times or more the area of the opening. The mask main body having this specific configuration can maintain the surface area of the mask main body while suppressing the mask main body from entering the operator's field of view and increasing the outer shape of the mask main body. Therefore, according to these nose cover portions and the area ratio, it is possible to achieve both the securing of visibility, the collection efficiency, and the ease of breathing. Moreover, the mask according to one aspect of the present invention can ensure the surface area of the mask body without necessarily entering the face of the mask body when worn, thus increasing the degree of freedom in designing the face seal. Accordingly, it is possible to provide a water absorbing portion for imparting water absorption to the face seal, and it is possible to suppress sticking of the face seal to the face due to the operator's sweat or the like. As described above, the mask according to one aspect of the present invention is not specialized for a specific function, and can exhibit all the performances required for the mask in a balanced manner by the above-described effects. Therefore, the mask according to one aspect of the present invention can improve safety and workability (work comfort / efficiency).

  With the mask according to one aspect of the present invention, safety, work comfort and efficiency can be improved.

It is a perspective view showing the state where the mask concerning one side of the present invention was worn. It is the perspective view which looked at the mask shown by FIG. 1 from another direction. It is a top view which shows an opening part. It is a figure which shows the cross section of the mask in the worn state. It is a figure which shows the cross section of the pleat provided in the mask. It is a figure which shows the cross section of a face seal. It is a figure which shows notionally the relationship of the item requested | required of a mask. It is a figure which shows the cross section of the mask in the worn state.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted.

  Various terms herein have the meanings defined below.

  “Including” means its definition that is standard in patent terminology and is an open-ended term that is almost synonymous with “comprising”, “having”, or “containing” . “Comprising”, “including”, “having” and “containing” and variations thereof are generally open-ended terms, but the present invention is more than “consisting essentially of” and the like. It may also be properly described using narrow terms, in that it excludes only objects or elements that adversely affect the performance of the respiratory mask of the present invention in performing its intended function. It is a term similar to the open-ended term.

  “Clean air” means a volume of ambient air that has been filtered to remove contaminants.

  “Contaminant” means particles (including dust, mist and fume) and / or other substances that may not generally be considered particles, but may be suspended in the air.

  “Bag-like” means any container-type shape that can adequately cover a person's nose and mouth.

  “External gas space” means a gas space in the ambient atmosphere through which exhaled gas enters after passing through the mask body.

  “Filtered face wear” is a mask body itself designed to filter air passing through the mask body, and a separate identifiable filter cartridge or insert molded filter to achieve this goal in the mask body Means the element is not attached or molded.

  “Filter” or “filter layer” means one or more layers of a breathable material, which are suitable for the main purpose of removing contaminants (such as particles) from the air stream passing therethrough.

  “Filter media” means a breathable structure designed to remove contaminants from the air that has passed through it.

  The “filter structure” means a structure including a filter medium or a filter layer.

  “Fit” means one or a combination of wearing, removing or adjusting the mask body.

  “Flange” means a protrusion having a surface area sufficient for a person to grip.

  A “mask body” is a breathable structure (a seam and joint that joins layers and components together) that fits over a person's mouth and nose and helps to separate and define the interior gas space from the exterior gas space Means).

  “Nose clip” means a mechanical device (other than a nose foam) adapted for use on a mask body, at least to enhance sealing around the wearer's nose.

  “Pleated” means a part that is designed or folded over so that it can be folded over itself.

  “Polymer” and “plastic” each mean a material that primarily contains one or more polymers and may also contain other components as well.

  “Basic function” means the function of removing contaminants from an air stream. This function is indicated by the collection efficiency.

  “Comfort” means a function that a wearer can comfortably wear for a long time. Factors relating to this comfort include comfort based on the contact state between the mask and the face, ensuring the wearer's field of view when wearing the mask, and breathing difficulty when wearing the mask. The wearing comfort is affected by the presence or absence of pain that may occur on the face in contact with the mask and the sticking of the mask on the face due to sweat or the like. The field of view of the wearer and the shape of the mask influence the securing of the field of view. Breathing is indicated by the inspiratory resistance related to the surface area of the filtration structure.

  The “nasal bridge contact portion” means a point in contact with the wearer's nasal bridge.

  The “chin contact portion” means a point that comes into contact with the wearer's chin.

  The “first axis” means a virtual axis that connects a point in contact with the nasal bridge (nasal bridge contact portion) and a point in contact with the jaw (chin contact portion) in the mask. The first axis is determined based on the shape that the mask can take in the state before wearing.

  The “second axis” means a virtual axis that passes through a point (nasal bridge contact portion) that contacts the nasal bridge in the mask and has an angle of 65 degrees or less with respect to the first axis. The second axis is determined based on the shape that the mask can take in the state before wearing.

  The “surface area of the mask body” means the area of the filtration structure that contributes to the function of removing contaminants. When the filtration structure has a concavo-convex structure, the “surface area of the mask body” referred to in this specification is larger than the apparent surface area of the mask body.

  The “water absorbing part” means a part having a function of holding a liquid. For example, a water absorbing layer made of nonwoven pulp is employed as the water absorbing portion. In addition, materials that can be used as the water absorbing portion will be described later.

  The “opening surrounded by the face contact edge” means a region surrounded by the face contact edge which is a closed line. When the face contact edge is included on the two-dimensional plane, the opening is a two-dimensional plane surrounded by the face contact edge. When the face contact edge is a three-dimensional curve, the opening is a minimal curved surface defined by the face contact edge. A minimal surface is a surface that minimizes or minimizes the area for a given boundary condition. An opening part is determined based on the shape which the mask in the state before wear can take.

  “Face contact edge” means the outer edge of the mask body, and when a person wears a respirator, this outer edge is generally located adjacent to the wearer's face. Specifically, it is a line that defines the outer edge of the portion that contacts the wearer. For the contact between the face contact edge and the wearer, the face contact edge directly contacts the wearer, and the face contact edge indirectly contacts the wearer via another member. including.

  FIG. 1 shows an example of a filter-type face wearing mask 1 on the wearer's M face. As shown in FIG. 1, the mask 1 is used to provide clean air for the wearer M to breathe. The mask 1 includes a mask main body 2, a strap 3, and a face seal 4 (see FIG. 2). The mask body 2 is attached to the face of the wearer M so as to cover the nose and mouth of the wearer M. The mask body 2 has a filtering structure 6 through which inspiration passes before entering the wearer's M respiratory system. The filtering structure 6 removes contaminants so that the wearer M can inhale clean air. The strap 3 is attached to the mask body 2. The position of the mask body 2 is maintained by the strap 3. The face seal 4 is joined to the mask body 2. The contact state between the mask 1 and the face is surface contact.

  The mask 1 may include a nose clip 7. The nose clip 7 is provided on the mask body 2 on the outer surface of the mask body 2 or under the cover web. The nose clip 7 is made of a flexible extremely soft metal or plastic. The nose clip 7 made of such a material can be adapted manually by the wearer M so as to match the contour of the nose of the wearer M. Further, the nose clip 7 may be made of aluminum, for example, an M-shaped nose clip shown in US Pat. No. 5,558,089 and US Design Patent No. 412,573 (Castiglion), etc. Other shapes may be used when viewed from above.

  As shown in FIGS. 2 and 3, the overall shape of the mask body 2 corresponds to the shape and structure of the filtration structure 6. The mask body 2 has an opening 8 (see FIG. 3) and has a shape that covers the nostril and mouth of the wearer M. A reinforcing frame may be attached to the inside of the mask body 2. The opening 8 is a region surrounded by the face contact edge 9 which is a closed line. When the face contact edge 9 is included on the plane, the opening 8 is a two-dimensional plane surrounded by the face contact edge 9. When the face contact edge 9 is a three-dimensional curve, the opening 8 is a minimal curved surface defined by the face contact edge 9. The face contact edge 9 includes a nasal bridge contact portion 11 that contacts the nasal bridge and a chin contact portion 12 that contacts the chin. As shown in FIG. 4, the mask body 2 is set with a first axis A1 and a second axis A2. The first axis A <b> 1 is a virtual axis that passes through the nasal bridge contact portion 11 and the chin contact portion 12. The second axis A2 is a virtual axis that passes through the nose bridge contact portion 11 and forms a predetermined angle θ with respect to the first axis A1. The predetermined angle θ extends from the nasal bridge contact portion 11 and the chin contact portion 12 on the first axis A1 to the chin contact portion 12 side from the nasal bridge contact portion 11 on the second axis A2. It means the angle between the half line segment. The angle θ formed by the first axis A1 and the second axis A2 may be 65 degrees or less, 63 degrees or less, or 60 degrees from the viewpoint of providing good visibility. Or less. The lower limit of the angle θ is not particularly limited, but can be set to 32 ° or more from the viewpoint of the mask shape actually used, and may be set to 35 ° or more or 38 ° or more.

  The mask body 2 has a nose cover portion 13 including a nasal bridge contact portion 11. The nose cover portion 13 covers at least a part of the nose bridge of the wearer M and is disposed between both eyes when worn. In FIG. 4, the nose cover portion 13 is integrated with the mask main body 2 to form one surface. Moreover, the nose cover part 13 can also be provided as a member independent of the mask body 2. Moreover, the nose clip 7 may be provided in the nose cover part 13. As shown in FIG. 4, when the mask main body 2 is viewed in cross-section when viewed from a direction perpendicular to the first axis A1 and the second axis A2, the nose cover portion 13 has the first axis A1 and the second axis. It is provided between A2. Since this nose covering part 13 tends to be out of the field of view of the wearer M, it is difficult to obstruct the field of view of the wearer M.

  The height of the mask body 2 is defined with reference to the first axis A1. The direction of the third axis A3 orthogonal to the first axis A1 is defined as the height direction. As shown in FIG. 4, the length from the first axis A <b> 1 to the position farthest from the first axis A <b> 1 along the third axis A <b> 3 is the height H of the mask body 2. The height of the mask main body 2 may be 70 mm or less, or 68 mm or less.

  The filtration structure 6 exhibits the performance required for the mask 1. The performance required for the mask 1 includes, for example, collection efficiency and intake resistance. Collection efficiency is one of the mask performances defined in official standards. The collection efficiency means the ability to remove fine dust having a predetermined particle size contained in the gas passing through the filtration structure 6, and is a basic performance of the mask 1. The collection efficiency is attributed to the basis weight of the filtration structure 6, the charging treatment of the filtration structure 6, the outer shape of the fibers constituting the filtration structure 6, and the area of the filtration structure 6. The mask 1 further satisfies the performance related to comfort after satisfying the collection efficiency defined in the official standard. The collection efficiency of the mask 1 is preferably 95% or more, and may be 96% or more and 98% or more. The collection efficiency of the mask 1 is that air containing dust is passed through the filtration structure 6 at a flow rate of 85 L (liter) per minute, and the concentration of dust contained in the air after passing through the filtration structure 6 is measured. Is obtained. As the dust, sodium chloride can be used. This sodium chloride has a median particle size distribution of 0.06 μm or more and 0.1 μm or less.

  The inspiratory resistance is a scale indicating ease of breathing when the mask 1 is worn. The greater the inspiratory resistance, the more difficult it is to breathe, and the smaller the inspiratory resistance, the easier it is to breathe. Therefore, it is desirable that the intake resistance of the mask 1 is smaller. The intake resistance of the mask 1 may be 50 Pa or less, 45 Pa or less, or 30 Pa or less. The intake resistance of the mask 1 is obtained by allowing air to pass through the filtration structure 6 at a flow rate of 40 L (liter) per minute and measuring the pressure difference between the upstream side and the downstream side with the filtration structure 6 as a boundary. The intake resistance is related to the collection efficiency. Specifically, increasing the collection efficiency tends to increase the inspiratory resistance and make it difficult to breathe. Thus, the ease of breathing and the collection efficiency are in a mutually contradictory relationship.

The intake resistance of the mask 1 is related to the surface area of the mask body 2. Specifically, when the surface area of the mask main body 2 is large, the inspiratory resistance becomes small, so that it is easy to breathe. On the other hand, if the surface area of the mask main body 2 is small, the inspiratory resistance increases, so that it becomes difficult to breathe. Thus, the ease of breathing and the surface area of the mask body 2 tend to conflict with each other. The surface area of the mask body 2, without compromising the collection efficiency from the viewpoint of improving the intake resistance, may also be 20000 mm ² or more, may be 25000 mm ² or more. In the mask according to one aspect of the present invention, the mask main body 2 is generally composed of the filtration structure 6, but may include a portion other than the filtration structure 6 (for example, a flange portion described later). In that case, the surface area of the filtering structure 6 is preferably at 20000 mm ² or more, more preferably 25000 mm ² or more.

  As an example of a means for increasing the surface area of the mask body 2, the mask body 2 can have at least one uneven structure. This concavo-convex structure is constituted by the filtration structure 6 and refers to a portion that can contribute to dust collection. Therefore, a portion that does not contribute to dust collection is not included in the uneven structure. For example, as shown in FIG. 1, the flange portion 2 a in which the filtration structures 6 are bonded together by welding is not included in the uneven structure. Therefore, the area of the mask body 2 that does not contribute to the collection of dust is not included in the area of the filtration structure 6. Such a portion that does not contribute to dust collection may obstruct the field of view and may be removed. In FIG. 1, the mask main body 2 has pleats 2b as an example of an uneven structure. The pleat 2 b has a structure in which the concave portion extends in a direction along the outer surface of the mask main body 2. As shown in FIG. 5, the pleat 2b has the filtration structure 6 folded back. Therefore, the area of the surface 6 s of the filtration structure 6 is larger than the area of the apparent virtual surface 2 s in the mask body 2. In addition to the pleats 2b, a corrugated structure can be used as an uneven structure for making the area of the surface 6s of the filtration structure 6 larger than the area of the apparent virtual surface 2s. This wavy structure is a structure in which a recess extends in a direction intersecting the outer surface of the mask body 2.

  As described above, when the outer shape of the mask main body 2 increases, the nose cover portion 13 tends to come off from between the first axis A1 and the second axis A2. In this case, for example, the nose cover portion 13 of the mask main body 2 can easily enter the field of view of the wearer M, and the view of the wearer M may be hindered. Therefore, there is a contradictory relationship between ease of breathing and securing visibility. On the other hand, according to the pleat 2 b of the mask body 2, the area of the filtration structure 6 can be made larger than the apparent surface area of the virtual surface 2 s in the mask body 2. While suppressing the expansion of the outer shape of the mask body 2, the surface area of the filtration structure 6 can be easily increased. Therefore, in the mask 1 according to one aspect of the present invention, by providing the pleat 2b, it is possible to facilitate breathing while suppressing the influence on the visual field.

  The surface area of the mask 1 and the area of the opening 8 have a predetermined ratio. The area of the opening 8 is a two-dimensional plane or a three-dimensional minimal curved surface. Typically, the surface area of the mask 1 may be 1.5 times or more with respect to the surface area of the opening 8 or may be 2 times or more. In the mask 1 having such a ratio, the area of the filtration structure 6 is increased, so that the inspiratory resistance is reduced and breathing is facilitated. In addition, although there is no restriction | limiting in particular about the upper limit of this ratio, It can be 10 times or less, 7 times or less, and 5 times or less.

  In some embodiments, the filtration structure 6 includes an inner cover web 6a, an outer cover web 6b, and a filter layer 6c. The filter layer 6c is sandwiched between the inner cover web 6a and the outer cover web 6b, and is protected by the inner cover web 6a and the outer cover web 6b. The inner cover web 6a and the outer cover web 6b prevent the fibers constituting the filter layer 6c from loosening and entering the inside of the mask. Air outside the mask 1 passes through the outer cover web 6b, the filter layer 6c, and the inner cover web 6a in this order, and is introduced into the internal gas space of the mask 1. Then, the air introduced into the internal gas space of the mask 1 is then sucked by the wearer M. The air exhaled from the wearer M passes through the inner cover web 6a, the filter layer 6c, and the outer cover web 6b in this order, and is discharged to the outside of the mask 1. The outer cover web 6b and the inner cover web 6a are made of a nonwoven material that provides a comfortable feeling on the side of the filtration structure 6 that is in contact with the face of the wearer M.

  The filtration structure 6 is a particle trapping type filter. Depending on the application, multiple layers of similar or different filter media can be used to construct the filtration structure 6. A filter that can be effectively used for the mask body 2 generally has a low inhalation resistance in order to minimize the breathing effort of the wearer M. The filter layer 6c has flexibility and sufficient shear strength to normally maintain their structure in the expected use conditions. Examples of particle trapping filters include one or more webs of fine inorganic fibers (such as glass fibers) or polymer synthetic fibers. Synthetic fiber webs include electret charged polymer microfibers produced by processes such as the meltblown process. Polyolefin microfibers formed from charged polypropylene are particularly useful for particle capture applications. Another filter layer 6c may include an adsorbent component for removing harmful or malodorous gases in the breathing air. The adsorbent may comprise an adhesive, binder, or powder or granules that are constrained to the filter layer 6c by a fibrous structure (US Pat. No. 6,334,671 (Springett et al.), And 3, 971,373 (Braun)). The adsorbent layer can be coated on a substrate such as a fibrous foam or a reticulated foam to form a thin and closely adhered layer. Examples of the adsorbent material include activated carbon (chemically treated or untreated), a porous alumina-silica catalyst base material, and alumina particles. An example of a sorbent filtration structure that can be adapted to various structures is described in US Pat. No. 6,391,429 (Senkus et al.).

The filter layer 6c is typically selected to achieve the desired filtration effect. The filter layer 6c typically removes particles and / or other contaminants at a high rate from the gas stream passing through the filter layer 6c. For the fibrous filter layer 6c, a fiber selected based on the type of substance to be filtered is usually selected so as not to bond to each other during the molding operation. As indicated, the filter layer 6c can be provided in a variety of shapes and forms, typically having a thickness of about 0.2 mm to 1 cm, more typically about 0.3 mm to 0.5 cm, It may also be a substantially planar web or corrugated to provide an extended surface area, for example, US Pat. Nos. 5,804,295 and 5,656,368. (Braun et al.). The filter layer 6c may also include a plurality of filter layers 6c joined together by an adhesive or any other means. Basically, any suitable material known (or later developed) for forming the filter layer 6c can be used as the filter material. Wente, Van A.M. Meltblown fiber webs, such as those taught in “Superfine Thermoplastic Fibers” (48 Indus. Engn. Chem., 1342 et seq. (1956)) in particular, Useful (see, eg, US Pat. No. 4,215,682 (Kubik et al.)). These meltblown fibers may be microfibers having an effective fiber diameter of less than about 20 [mu] m ([mu] m) ("blown microfiber" is referred to as BMF), generally about 1 [mu] m to 12 [mu] m. Effective fiber diameter is determined by Davies, C .; N. , “The Separation of Airline Dust Particles”, Institution of Mechanical Engineers, London, Bulletin 1B, 1952. For example, a BMF web comprising fibers formed from polypropylene, poly (4-methyl-1-pentene), and combinations thereof. Charged fibrillated film fibers taught in US Pat. No. 31,285 (van Turnhout) may also be suitable, and rosin-wool fiber webs and glass fiber or solution blown webs, or electrostatic Spray fibers, particularly in the form of microfilms, may also be suitable. Charges are described in US Pat. Nos. 6,824,718 (Eitzman et al.), 6,783,574 (Angadjivand et al.), 6,743,464 (Insley et al.), 6,454,986 and 6,406,657 (Eitzman et al.), And 6,375,886 and 5,496,507 (Angadjivand et al.). As can be seen, it can be imparted to the fiber by contacting the fiber with water. The charge may also be due to corona charging as disclosed in US Pat. No. 4,588,537 (Klasse et al.) Or as disclosed in US Pat. No. 4,798,850 (Brown). It may be imparted to the fiber by tribocharging. In addition, additives can be included in the fibers to enhance the filtration performance of webs produced by the hydrocharging process (see US Pat. No. 5,908,598 (Rousseau et al.)). In particular, by arranging fluorine atoms on the fiber surface of the filter layer 6c, the filtration performance in an oily mist environment can be improved (US Pat. Nos. 6,398,847B1, 6,397,458B1, No. 6,409,806B1 (Jones et al.)). The typical basis weight of the electret BMF filter layer is about 10 g to 100 g per m ² . For example, when charged by the technique described in the '507 patent (Angadjivand et al.) And also Jones et al. In the case of containing fluorine atoms as described in US Pat. No. 5,849, the basis weights are about 20 g / m ^{2 to} 40 g / m ² and about 10 g / m ^{2 to} 30 g / m ² respectively.

The inner cover web 6a can be used to provide a smooth surface to contact the face of the wearer M, and the outer cover web 6b can enclose free fibers in the mask body 2, or Can be used for aesthetic reasons. The outer cover web 6b can function as a prefilter when placed outside (or upstream) of the filter layer 6c, but typically has some substantial filter effect on the filtration structure 6. Does not provide. In order to obtain a suitable degree of comfort, the inner cover web 6a has a relatively low basis weight and is formed from relatively fine fibers. More specifically, the inner cover web 6a may be made to have a basis weight of about 5 g / m ^{2 to} 50 g / m ² (typically 10 g / m ^{2 to} 30 g / m ² ), and the fibers Less than 0.389 g / km (typically less than 0.222 g / km (2 denier)), more typically less than 0.111 g / km (1 denier), but 0.0111 g / Km (0.1)) may be exceeded. The fibers used for the inner cover web 6a often have an average fiber diameter of about 5 μm to 24 μm, typically about 7 μm to 18 μm, more typically about 8 μm to 12 μm. The cover web material has a degree of elasticity (typically between 100% and 200%, but not necessarily when broken), and may be plastically deformable.

  Suitable materials for the inner cover web 6a and the outer cover web 6b include blown microfiber (BMF) materials, particularly polyolefin BMF materials such as polypropylene BMF materials (including polypropylene blends and mixtures of polypropylene and polyethylene). It is done. A suitable manufacturing process for BMF materials for cover webs is described in US Pat. No. 4,013,816 (Sabee et al.). Webs may be formed by collecting fibers on a smooth surface, typically a smooth surface drum or rotating collector (US Pat. No. 6,492,286 (Berrigan et al.)). See Spunbond fibers can also be used.

The inner cover web 6a and the outer cover web 6b can be made from polypropylene or a polypropylene / polyolefin blend containing more than 50% by weight polypropylene. These materials provide the wearer M with a high degree of softness and comfort, and when the filter material is a polypropylene BMF material, it is secured to the filter material without the need for an adhesive between the layers. It has been found to keep. Suitable polyolefin materials for use in the inner cover web 6a and the outer cover web 6b include, for example, a single polypropylene, a mixture of two polypropylenes, a mixture of polypropylene and polyethylene, polypropylene and poly (4-methyl-1 A mixture of pentene) and / or a mixture of polypropylene and polybutylene. An example of a cover web fiber is Polypropylene BMF “Escorene 3505G” manufactured by Exxon Corporation made from polypropylene resin, which has a basis weight of about 25 g / m ² and a fiber denier of 0.2-3. 1 (average of measurements over 100 fibers of about 0.8). Another suitable fiber is polypropylene / polyethylene BMF (manufactured from a mixture containing 85% resin “Escorene 3505G” and 15% ethylene / α-olefin copolymer “Exact 4023” (also from Exxon Corporation)). This has a basis weight of about 25 g / m ² and an average fiber denier of about 0.8. Suitable spunbond materials are available from Corovin GmbH (Peine, Germany) under the trade names "Corsoft Plus 20", "Corsoft Classic 20", and "Corobin PP-S-14", and the card polypropylene / viscose is J. et al. W. It is available from Suominen OY (Nakila, Finland) under the trade name “370/15”.

  The inner cover web 6a and the outer cover web 6b used in the present invention have very few fibers protruding from the web surface after processing and thus have a smooth outer surface. Examples of inner cover web 6a and outer cover web 6b that may be used in the present invention include, for example, U.S. Patent Nos. 6,041,782 (Angedjivand), 6,123,077 (Bostock et al.) And International Publication No. WO 96 / 28216A (Bostock et al.).

  As shown in FIG. 2, the face seal 4 reduces the pressure load acting on the face by making the contact state between the mask 1 and the face planar. When the mask 1 is worn, the face seal 4 extends radially inward and comes into contact with the face of the wearer M. The face seal 4 is an annular sheet member having flexibility. The face seal 4 is disposed so as to cover the opening 8 with respect to the mask body 2. The face seal 4 has an outer peripheral edge 4 a bonded to the face contact edge 9. Examples of the method of joining the face seal 4 to the mask body 2 include welding, and specific examples of the welding include thermal welding. Therefore, the heat-welded portion 4 b of the face seal 4 can be regarded as the heat-welded portion 9 a of the face contact edge 9. The inner peripheral edge 4c of the face seal 4 defines a seal opening 15 in which the nose and mouth are disposed. The seal opening 15 is formed by punching. The inner peripheral edge 4c that forms the seal opening 15 is subjected to end processing. Examples of the edge processing method include adhesion and welding. The size of the seal opening 15 is not particularly limited as long as the nose and the mouth can be inserted.

The face seal 4 has a water absorption part and retains moisture. This moisture includes, for example, sweat and moisture secreted from the face of the wearer M. The water absorption of the water absorbing portion in the face seal 4 is obtained by causing the face seal 4 to absorb water, comparing the weight of the face seal 4 before and after water absorption, and determining the amount of water absorption per 1 m ² . As the water absorption (water absorption amount) of the water absorption part (specifically, the water absorption layer 14b described below), typically, 0.5 kg or more of water can be held per 1 m ² , and in one aspect, 1 m ² It is possible to hold 1.0 kg or more or 3.0 kg or more of water. Moreover, generally the upper limit of the amount of water absorption in a water absorption part is 15 kg or less per 1 m < ² >, 12 kg or less, 8.0 kg or less.

As shown in FIG. 6, in one embodiment, the face seal 4 has a laminated structure. The face seal 4 includes a cover web 14a that is a surface layer material (the face side of the wearer M), a water absorption layer 14b that is a water absorption portion, and a backing film 14c that is a back material (mask body side). The cover web 14a contacts the face when worn. The cover web 14a may be a water permeable nonwoven fabric including hydrophobic fibers. As the cover web 14a, for example, a polypropylene non-woven fabric, a polyethylene non-woven fabric, a polyester non-woven fabric, a polyethylene-polypropylene non-woven fabric, a polyethylene terephthalate spong-band non-woven fabric, a non-woven fabric in which a plurality of polyolefin fibers are combined can be employed. The basis weight of the nonwoven fabric, generally can be ^{10g / m 2 ~40g / m 2} . These non-woven fabrics may be subjected to a hydrophilic treatment by mixing a surfactant. The backing film 14 c forms the base of the face seal 4. Examples of the backing film 14c include a polyolefin-based film, such as a polyethylene film. The thickness of the backing film 14c is generally 15 μm to 100 μm. In FIG. 6, the water absorption layer 14b exists between the cover web 14a and the backing film 14c. Examples of the water absorbing layer 14b include pulp materials containing non-woven pulp and the like. Further, as other examples of the water absorbing layer 14b, for example, a mixed nonwoven fabric of pulp and a water absorbing polymer, a compressed sheet of pulp, a water absorbing paper, a rayon nonwoven fabric and the like can be adopted. In addition, as a water absorption part, structures other than an above-mentioned water absorption layer are also possible, and a water | moisture content is contained by containing a superabsorbent polymer (SAP: superabsorbent polymer) and a superabsorbent polymer fiber (SAF: superabsorbent fiber). It is good also as a structure to hold | maintain.

  The strap 3 can be made from a variety of materials such as thermoset rubber, thermoplastic elastomers, braided or knitted yarn / rubber combinations, inelastic braided components, and others. The strap 3 may be formed from an elastic material, for example, an elastic braided material. The strap 3 can be expanded more than twice its full length and return to its relaxed state. The strap 3 can also extend up to 3 or 4 times its relaxed length and can return to its original state without any damage when the tension is removed. Therefore, the elastic limit is preferably 2 times, 3 times, or 4 times or more the length of the strap 3 in the relaxed state. Typically, the strap 3 has a length of about 20 cm to 45 cm, a width of 3 mm to 10 mm, and a thickness of about 0.5 mm to 2.0 mm. The strap 3 may have a plurality of parts that can be joined together by fasteners or buckles. For example, the strap 3 may have first and second parts joined together by fasteners that can be quickly separated by the wearer M when removing the mask body 2 from the face. An example of a strap 3 that can be used in connection with the present invention is shown in US Pat. No. 6,332,465 (Xue et al.). Examples of fastening or clasp mechanisms that can be used to join one or more portions of the strap 3 together are described, for example, in US Pat. No. 6,062,221 (Brostrom et al.), No. 5 below. 237,986 (Seppala), and European Patent 1,495,785A1 (Chien).

  Here, the evaluation items of the mask 1 will be described while exemplifying the masks according to Comparative Examples 1 to 4. Comparative Example 1 is a commercially available mask. The mask of Comparative Example 1 has a cup shape and includes a face seal. Note that the mask of Comparative Example 1 does not include a portion corresponding to pleats. Comparative Example 2 is another commercially available mask. The mask of Comparative Example 2 has a cup shape and includes a face seal. The mask of Comparative Example 2 has a structure that can be folded in half. Note that the mask of Comparative Example 2 does not include a portion corresponding to pleats. Comparative Example 3 is still another commercially available mask. The mask of Comparative Example 3 is cup-shaped and has pleats. Note that the mask of Comparative Example 3 does not include a face seal. Comparative Example 4 is another commercially available mask. The mask of Comparative Example 4 is foldable and has pleats. Note that the mask of Comparative Example 4 does not include a face seal. Note that Example 1 is a mask 1 according to one embodiment of the present invention.

  The masks according to Comparative Examples 1 to 4 have the structures and characteristics shown in Table 1. Hereinafter, comprehensive evaluation of the masks 1 according to Comparative Examples 1 to 4 and Example 1 is performed from the viewpoint of safety and workability (work comfort and efficiency), and the results are evaluated in five stages ( The higher the number, the better the evaluation result). Items related to safety include “collection efficiency” and “securing visibility”. Items relating to workability (work comfort / efficiency) include “wear comfort” and “breathing difficulty”.

  The collection efficiency is a measurement value based on a measurement method defined in an official standard. “Securing the field of view” is an evaluation item regarding the penetration of the mask 1 into the field of view of the wearer M. This evaluation item relates to the angle θ formed by the first axis A1 and the second axis A2. It should be noted that the height of the mask 1 may also affect “securing the field of view”. The angle in “Securing the field of view” was an angle φ (see FIG. 4) between the first axis A1 and a portion corresponding to the nose cover portion 13. The angle of Comparative Example 4 is a folding type, and was measured under the condition that it was correctly attached to the human head used for the national certification test of the dust mask (with no gaps so that dust does not enter the mask). Value. Further, the height was a dimension measured using the definition of the height H in the present embodiment. In addition, the height of the comparative example 4 was estimated based on relative ratio with various masks at the time of mounting | wearing a human head.

  “Comfort” is an evaluation item related to pain in long-time wearing and sticking of the face seal to the face. This evaluation item relates to the presence or absence of the face seal 4 and the presence or absence of water absorption. As shown in Table 1, in the item of wearing comfort, a mask having a face seal or a structure corresponding thereto is “present”, and a mask having no face seal or a structure corresponding thereto is “no”. Further, in the mask having a face seal or a structure corresponding thereto, a mask having a water absorbing portion was set to “Yes”, and a mask having no water absorbing portion or not having sufficient performance as a water absorbing portion was set to “No”.

“Breathing” is an evaluation item regarding the ease of breathing that the wearer M feels when wearing a mask. This evaluation item relates to intake resistance. The inspiratory resistance in the item of breathlessness is a value measured using the inspiratory resistance measuring method in the present embodiment. The area ratio is a ratio of values obtained based on the definition of the surface area of the mask body and the area of the opening in the present embodiment.

  FIG. 7 shows qualitatively the evaluation results of the masks C1 to C4 of Comparative Examples 1 to 4 shown in Table 1 and the evaluation result of the mask 1 of Example 1 according to this embodiment using three-dimensional coordinates. Show. In FIG. 7, the first axis B1 indicates comfort, the second axis B2 indicates breathlessness, and the third axis B3 indicates securing of visibility.

  As shown in Table 1 and FIG. 7, first, the masks of Comparative Examples 1 to 4 are all masks that meet official standards, and have a collection efficiency of 95% or more. The mask C1 of Comparative Example 1 has a relatively small angle and height, which is advantageous in terms of ensuring visibility. However, although the mask C1 has a face seal and has a structure in which the pressure load on the face is reduced, the mask C1 does not have a water absorbing portion, and thus does not have sufficient water absorption. It was disadvantageous in terms of wearing comfort in time work. The mask C2 of Comparative Example 2 had a relatively small angle, and was advantageous in terms of ensuring visibility. However, the mask C2, like the mask C1, has a disadvantage in that the face seal does not have sufficient water absorption and is comfortable to wear for a long time. On the other hand, the mask C3 of Comparative Example 3 is advantageous in terms of a structure that does not cause breathing because the suction resistance is small and the area ratio is large. However, the mask C3 has a relatively large angle, which is disadvantageous in terms of ensuring visibility, and since it does not have a face seal, it is also disadvantageous in terms of wearing comfort. The mask C4 of Comparative Example 4 has a relatively small suction resistance and has a structure that is not stuffy like the mask C3. However, the mask C4 does not have a face seal and is disadvantageous in terms of wearing comfort.

  The masks C1 to C4 of Comparative Examples 1 to 4 had a collection efficiency that is a basic performance. On the other hand, the masks C1 to C4 of Comparative Examples 1 to 4 had advantageous items as well as disadvantageous items in terms of ensuring visibility, wearing comfort, and breathing difficulty. Therefore, the masks C1 to C4 of Comparative Examples 1 to 4 are not sufficient to improve all the performances related to safety and workability.

  Here, for example, a case where a mask having a face seal is improved is assumed. According to the mask provided with the face seal, the pressure load on the face is reduced, which is advantageous in terms of wearing comfort. On the other hand, in a mask provided with a face seal, the wearer's face generally does not easily enter the mask body when worn. In this case, if the surface area of the mask body is further maintained from the viewpoint of securing the collection efficiency, the outer shape (apparent) shape of the mask body tends to increase (see the mask 16 according to Comparative Example 5 in FIG. 8). . Also, from the viewpoint of ensuring ease of breathing, the outer shape of the mask body is similarly increased. However, when the outer shape of the mask main body is enlarged, the mask main body enters the wearer's field of view, which may hinder the wearer's visual field during work. Therefore, in a mask provided with a face seal, there may be a conflicting problem between the point of collection efficiency and ease of breathing and the point of view visibility. On the other hand, if a structure allowing the wearer's face to enter the mask body is possible (see mask 17 according to Comparative Example 6 in FIG. 8), the outer shape of the mask body is maintained in order to maintain the collection efficiency and ease of breathing. There is no need to enlarge the shape. However, the face seal is required to have sufficient flexibility and thinness so that the face seal can enter the mask body after having the face seal. Therefore, for the face seal, it is necessary to select a highly flexible material or reduce the thickness of the face seal. Accordingly, the degree of freedom in designing the face seal is reduced, and it becomes difficult to provide a water absorbing portion that imparts water absorbing performance to the face seal.

  A mask according to one aspect of the present invention includes a mask body having a nose cover portion and a face seal fixed (joined) to a face contact edge of the mask body, and the nose cover portion contacts the wearer's nasal bridge. Between the first axis passing through the nasal bridge contact portion and the jaw contact portion contacting the wearer's jaw, and the second axis passing through the nasal bridge contact portion and having an angle of 65 degrees or less with respect to the first axis. The surface area of the mask main body provided is 1.5 times or more than the area of the opening surrounded by the face contact edge, and the face seal has a water absorbing portion.

  Since the face seal is joined to the mask main body, the mask is in surface contact with the wearer's face. Therefore, since the pressure load on the face generated during wearing is reduced, pain during long-time wearing can be reduced. On the other hand, a mask provided with a face seal may cause conflicting problems of collection efficiency and ease of breathing, and securing a field of view. Therefore, in the mask according to one aspect of the present invention, the nose cover portion is placed between the first axis and the second axis in order to satisfy both the characteristics of securing the field of view, collection efficiency, and ease of breathing. Further, the surface area of the mask body is 1.5 times or more the area of the opening. The mask main body having this specific configuration can maintain the surface area of the mask main body while suppressing the mask main body from entering the operator's field of view and increasing the outer shape of the mask main body. Therefore, according to these nose cover portions and the area ratio, it is possible to achieve both the securing of visibility, the collection efficiency, and the ease of breathing. Moreover, the mask according to one aspect of the present invention can ensure the surface area of the mask body without necessarily entering the face of the mask body when worn, thus increasing the degree of freedom in designing the face seal. Accordingly, it is possible to provide a water absorbing portion for imparting water absorption to the face seal, and it is possible to suppress sticking of the face seal to the face due to the operator's sweat or the like. As described above, the mask according to one aspect of the present invention is not specialized for a specific function, and can exhibit all the performances required for the mask in a balanced manner by the above-described effects. Therefore, the mask according to one aspect of the present invention can improve safety and workability (work comfort / efficiency).

  Specifically, in the mask 1 according to an embodiment of the present invention, the face seal 4 is joined to the mask body 2, so that the mask 1 comes into contact with the face of the wearer M in a planar shape when worn. Become. Therefore, since the pressure load on the face generated during wearing is reduced, pain during long-time wearing can be reduced. Further, the nose cover portion 13 is provided between the first axis A1 and the second axis A2. In the mask 1 described as an embodiment of the present invention, the angle between the first axis A1 and the nose cover portion 13 is 59 degrees (see Table 1). Therefore, since the nose cover part 13 is difficult to enter the field of view of the wearer M when worn, a good field of view can be secured.

  In addition, since the surface area of the mask body 2 is twice as large as the area of the opening 8 (see Table 1), it is possible to reduce breathlessness while ensuring a good field of view. Such a relationship between the surface area of the mask main body 2 and the area of the opening 8 is realized, for example, by providing the filtration structure 6 with the pleats 2b. The mask 1 shown in FIG. 8 has a surface area equivalent to that of the mask 16 according to the comparative example 5, and its height H is reduced to prevent the wearer M from entering the field of view (FIG. 8). Mask 1). Further, it is not necessary to dispose the face deeply like the mask 17 according to the comparative example 6 while having the same surface area as the mask 16 according to the comparative example 5. Therefore, it is possible to provide the water absorption layer 14b with the face seal 4 having a laminated structure, and to keep the face seal 4 wet by holding moisture such as sweat. Therefore, sticking of the face seal 4 to the face can be suppressed, and a long-time operation can be comfortably performed. For this reason, as shown in Table 1 and FIG. 7, the mask 1 according to one embodiment can obtain good evaluations in all items of wearing comfort, ensuring visibility, and breathing difficulty. Therefore, the mask 1 can maintain comprehensive safety and comfort for a long time.

A water absorption part is good also as absorbing 0.5 kg or more of water per 1 m ² . In an embodiment, 1.0 kg or more or 3.0 kg or more of water may be absorbed per 1 m ² . The upper limit of the water absorption in the water portion, generally, 15 kg or less per 1 m ^2, 12 kg or less, or less 8.0 kg. The mask body may have an intake resistance of 50 Pa or less. The surface area of the mask body may be 20000 mm ² or more. Further, the collection efficiency of the mask body may be 95% or more. Further, the height of the mask body in a direction orthogonal to the first axis may be 70 mm or less.

  The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Mask, 2 ... Mask main body, 2a ... Flange part, 2b ... Pleat, 3 ... Strap, 4 ... Face seal, 6 ... Filtration structure, 7 ... Nose clip, 8 ... Opening part, 9 ... Face contact edge, 9a DESCRIPTION OF SYMBOLS ... Thermal welding part, 11 ... Nasal bridge contact part, 12 ... Jaw contact part, 13 ... Nose cover part, 15 ... Seal opening, 14b ... Water absorption layer, A1 ... 1st axis, A2 ... 2nd axis, A3 ... 1st 3 axis, M ... Wearer.

Claims (6)

A mask body having a nose cover;
A face seal joined to the face contact edge of the mask body;
With
The nose cover part includes a nasal bridge contact part that contacts the wearer's nasal bridge, a first axis that passes through the chin contact part that contacts the wearer's chin, and an angle that passes through the nasal bridge contact part and is relative to the first axis. Is provided between the second axis and 65 degrees or less,
The surface area of the mask body is at least 1.5 times the area of the opening surrounded by the face contact edge,
The face seal is a mask having a water absorption part. The said water absorption part is a mask of Claim 1 which absorbs the water | moisture content of 0.5 kg or more per 1 m < ² >.   The mask according to claim 1, wherein the mask body has an intake resistance of 50 Pa or less. The surface area of the said mask main body is 20000 mm < ² > or more, The mask as described in any one of Claims 1-3.   The mask according to any one of claims 1 to 4, wherein the collection efficiency of the mask body is 95% or more.   The mask according to any one of claims 1 to 5, wherein the mask body has a height in a direction orthogonal to the first axis of 70 mm or less.

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